How to expose dotnet functionality to BaristaCore scripts.

There are currently a few ways of exposing native .net functionality to Barista scripts:

Creating the corresponding objects directly

By using the JsValue derived objects, one can manually create the corresponding JavaScript objects

For example, within a custom Barista Module:

[BaristaModule("adder", "The answer is...")]
public class AdderModule : IBaristaModule
{
    public Task<object> ExportDefault(BaristaContext context, BaristaModuleRecord referencingModule)
    {
        var fnAdd = ctx.CreateFunction(new Func<JsObject, int, int, int>((thisObj, a, b) =>
        {
            return a + b;
        }));
        return Task.FromResult<object>(fnAdd);
    }
}

Output Object

Another other way is to export an object, BaristaCore with automatically convert the object to a JavaScript object.

[BaristaModule("native-object", "Returns a native .net object that can be used within scripts.")]
public class NativeObjectModule : IBaristaModule
{
    public Task<object> ExportDefault(BaristaContext context, BaristaModuleRecord referencingModule)
    {
        var foo = new CarlyRae() { Name = "Kilroy" };
         return Task.FromResult<object>(foo);
    }
}

Types can be directly exported as well and are converted to JavaScript prototypes.

This probably deserves a whole entire section on the conversion process. However, for right now:

Classes => JS Constructor Function

Static Properties => properties defined on the constructor

Static Methods => functions defined on the constructor

Static Events => adds static addEventListener/removeEventListener/removeAllEventListeners on the constructor

Instance Properties -> properties defined on the prototype

Methods => functions defined on the prototype

Events => adds static addEventListener/removeEventListener/removeAllEventListeners to the prototype.

Classes marked as IEnumerable expose a Symbol.iterator property on the prototype as described in the JavaScript iteration protocol

A number of attributes control the conversion process:

[BaristaIgnore] => ignore the property/method/event

[BaristaProperty(string name, enumerable, configurable, writable)] => define the name and how the property is exposed.

The two mentioned techniques can be combined for maximum effect. See the fetch module for an example of this.